it the turbo then.

[Fergus]

It's simple, no need to fear at all.
Just make sure you take it slow, in the right place and use plenty of lube
Take it real slow tapping it to ensure the threads are solid and use a metal epoxy on it to (I forget the name of it).

Here's the FM write up on it: http://www.flyinmiata.com/support/instr ... turbos.pdf
It's on page 13. Note that in the pic with the red lines, if you place the return port to much to the right it will hit the oil pick up inside the sump.

If your having a tech day I might turn up, I have a tapping bit for the sump if its the 'normal' return port size.